Simple answer to your question is weight saving ! The external covers are really under no major stress, so it certainly makes sense to me.

I had a look at the Bevel Rubber web site, and it sure looks the goods if you have the cash available. It prompted me to have a look around at the alternatives, but there doesn't appear to be any. ???? ( Roundcase )

Mario Sassi appears to make a squarecase Mille version, but that's all I could find. Steve has "some" bits, as does Gowanlocks, Road & Race and the new Vee Two site is only a maketing page. it has no links to products at all.

G'day Rick - what do you think the weight difference would be between the normal alloy and magnesium covers? I wouldn't have thought that it would make much real-world difference, particularly because it is "sprung" weight. The same weight saving on the forks or wheels might improve the ride and handling though.

I've got to agree with you that the roundcase dry clutch kit that Mr Birch is offering really does look pretty schmick, especially with the straight cut primary gears. It would be interesting to get an idea of the power saving. And I wonder what it sounds like when the lever is pulled? I've heard some pretty loud dry clutches.

Yeah, would be interesting to know what the actual difference is. I'm certainly no authority, but the mag bits I have seen and felt in the past were incredibly light, as in less than half the weight of the Alloy equivalent. From memory, I recall the Vee Two covers were around 2 KGs so I'm guessing maybe 1 KG or less for the Mag cover.

I agree, on it's own, stuff all difference, but as my racing mates keep telling me, "every bit counts " especially given many of the new MX bikes are going to magnesium covers as well, so there must be something in it.

It's a mute point for me anyway as I don't race a roundcase, but his website blurb seems to indicate a Squarecase unit on the way, so it will be interesting to watch the progress.